Tackle-block



UNITED STATES PATENT OFFICE.

FRANK X. ROUS SEAU, OF DETROIT, MICHIGAN.

TACKLE-BLOCK.

- SPECIFICATION forming part of Letters Patent No. 476,078, dated May31, 1892.

Application filed September 28, 1891. $erial No. 407,035. (No model.)

T at whom it may concern.-

Be it known that I, FRANK X. ROUSSEAU, a citizen of the United States,residing at Detroit, in the county of Wayne and State of Michigan, haveinvented certain new and usefullmprovements in Tackle-Blocks; and I dodeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to new and useful improvements in safetytackle-blocks; and it consists in a certain construction and arrangementof parts, as hereinafter fully set forth,

the essential features of which being pointed out particularly in theclaims.

The object of the invention is to produce a tackle-blockthat is strongand compact and that is provided with an automatic clutch that, upon thecessation of pull upon the rope to raise the weight, will grip or bindthe rope to hold in suspension a load or weight at any degree ofelevation. This object is attained by the mechanism illustrated in theaccompanying drawings, in which Figure 1 is a side elevation of adoubleblock tackle provided with my improved features, a portion of theshell of the upper or stationary block and the shank of its hook beingbroken away to show the location of parts. Fig. 2 is an enlargedperspective view of the eccentric wedge or clamp inverted, showing theserrated groove in its under face that receives and binds the rope. Fig.3 is a central vertical section through the shank of the hook and thestationary block as taken on dotted line 3 of Fig. 1.

Referring to the letters of reference, A designates the stationary blockor shell, which is made, preferably, of metal and is composed of theside plates B and the central dividingplate 0. 1

D D designate the sheaves, that are located one on each side of thedividing-plate C, between the side plates B B, and are journaled on thepintle a, that passes centrally through the plates of the shell and isriveted therein, as shown in Fig. 3. The lower edges of the plates ofthe shell are secured by the pin a, that passes therethrough and throughthe shank e of the eye I), whereby said eye is suspended from said pin,the shank of said eye 19 being divided through its center to receive thelower edge of the central dividing-plate 0, thereby securing said plateat the bottom against lateral play and holding it centrally in place andalso distributing the weight equally between or upon all of the plates,as the draft comes between each of the side plates and the centralplate. The plates of the shell at their upper edges are secured by thepih cl, thatpasses therethrough and through the bifurcated shank h ofthe hook F, pivotally coupling said hook to the block or shell, the forkof said hook being provided with a groove or recess 8, (see Fig. 3,)that receives the upper edge of the dividing-plate C to sesure itagainst lateral displacement at the top.

H designates the gravitating clampingwedges, of which there are two, andwhich are provided in their under faces with a serrated gorge or groovef, as shown in Fig. 2. Said wedges are eccentrically pivoted on the pind, one on each side of the dividing-plate O. The hubs of saidwedges,through which the pin d passes, extend between the forks t of thebifurcated shank of the hook F, as shown in Fig. 3, and formed upon saidhub is a projecting arm I, to which is attached a pull-cord 0. By makingthe shank of the hook bifurcated and leaving forks t t of sufficientthickness or strength the side plates B B can be firmly secured theretoby means of the rivet cl without any danger of forcing them to gether ortoward each other so far as to clamp or bind the wedges H H, which wouldprevent their action by gravity after they were once forced away fromthe rope by the pull-cord 0, and by providing the bottom of thebifurcation with a groove 8' the end of the middle plate (J will alwaysbe held equidistant from the side plates i3 and the forks 25, thusavoiding any possibility of. the Wedges becoming caught or bound whenthe hook is moved upon its pivotal point (I. The weighted clamping-wedgeof the clamping device H is formed with a convex periphery, the curve ofthe periphery being in an opposite directionto the curve of the sheave.This leaves the nose or forward end of the weighted portion adjacent tothe sheave, while the opposite extremity or heel turns upward and awayfrom the sheave. This construction permits the use of any desired sizeof hoisting-rope. The hub 'ItOf the wedges are made thin, so as to passbetween the forks tof the hook, forming a shoulder s, that extends underthe ends of said forks, so that the body of said wedges fill the shell,being equal in thickness to that of the sheaves D, above which saidwedges are suspended, the serrated gorge f in the Wedges registeringwith the groove in the sheaves between which the rope K runs, as shownin Fig. 3. This construction of the wedges permits of the plates B Bbeing placed upon the outside of the forks of the bifurcated shank ofthe hooks F, which will permit of the use of wide pulleys between theplates, and at the same time will permit of the groovein the wedgesbeing thrown to one side sufficiently to register with the groove in thepulley to bind the rope equally upon all sides, which could not be doneif the wedges were no thicker throughout than they are between the forkst t.

L designates the running block, having the hook M, to which the load tobe raised is to be attached. Said block is joined to the standing blockA by means of the rope K, which is rove through said blocks over thesheaves therein in the ordinary manner. By eccentrically mounting thewedges H upon the pin d the tendency of the body portion of the wedge isto swing downward, which keeps it in contact with the rope K, passingover the sheave D. The arrangement is such, however, that when adownward pull is exerted on the hauling end of the rope to raise theload the wedge will swingoutward, permitting the rope to run freely overthe sheave, but at the cessation of pull on said rope the wedge Will bedrawn inward and clamp the rope upon the periphery of the sheave with aforce proportionate to the weight of the load, there by securelysupporting the load at any elevation. Upon'the resumption of the pullupon said rope the wedge will swing out, freeing the rope and permittingthe load to again ascend. \Vhen it is desired to lower the weight, adownward pull is exerted upon the cord 0, drawing down the arm I andswinging outward the wedge H, as shown by dotted lines in Fig. 1, thusfreeing the rope K, when by slacking away on the hauling end of saidrope the block L will run down, thus lowering the weight- Upon releasingthe cord 0 the wedge will again clamp the rope and sustain the weight,as before described.

In a double sheave-block by the employment of the two independentwedges, as shown in Fig. 3, the clamping of the rope is made doublysecure, for should one wedge permit the rope to slip the otherone willhold it, and by means of the eccentric action of the wedges they willclamp ropes of various sizes with the same efficiency.

It will be understood that this improved safety-clamp may be attached tosingle blocks as well as to double blocks, as shown.

This improved tackle-block is especially adapted for supporting swinging'scafiolds used for painting the sides of high buildings and other workof that kind where the scaffolding requires to be raised and lowered, asby the use of this tackle the scafiold may be securely supported at anyelevation and readily adjusted when desired.

Having thus fully set forth my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In a tackle-block, the combination, with the shell, of a sheavejournaled therein and a hook pivotally secured to the upper end, theshank of which hook is bifurcated, an eccentric clamping devicepivotally secured upon the pivotal pin at the top directly above saidsheave and in a vertical line with the axis thereof, said clampingdevice having a reduced h uh for fittin g between the forks of thebifurcated shank and having a lever-arm extending from it in onedirection and a weighted portion extending from it in the oppositedirection, said weighted portion having an arc-shaped clamping-peripherythe curvature of which is opposite to the sheath and formed with a nosein normal contact with the hoisting-cable and a free upturned heel atthe opposite extremity, said surface being substantially of the samewidth as the width of the sheave and provided with a concave serratedgroove, said clamping device being pivoted upon said pivotal pin abovethe nose of the weighted portion, the construction being such that apull on said lever-arm may throw the nose of the clamping deviceentirely out of contact with the hoisting-cable, substantially assetforth.

2. A tackle-block comprising the shell consisting of three plates andthree bolts through them for holding them together, two sheavesjournaled upon the middle bolt, one upon each side of the central plate,a hook pivotally secured upon the upper bolt, the shank of which hook isbifurcated and provided with a groove in the bottom of the bifurcation,the upper end of the central plate fittingin said groove, two eccentricclamping devices upon said bolt, one upon each side of the centralplate, each one of which is reduced at the hub to fit between the forkand the central plate, and the main portion being of the same width asthe sheave and consisting of an eccentric segment the curvature of whichis opposite to that of the sheave and the surface provided with aconcave spirally-serrated groove to register with the groove of thesheave, and an eye upon the lower bolt, the shank or up per wall ofwhich is divided through its center to receive the lower end of thecentral plate, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

FRANK X. ROUSSEAU.

\Vitnesses:

Louis 0. OHAPoToN, 0. WHEELER.

IIO

